Someone who is VERY social and easygoing; can be either a male or a female. Usually these people don’t belong to a particular group, but rather jump from one group to another. They are somewhat accepted in all of them, but don’t really have any deep friendship connections in any of them.

V: “I’ve been a real “social butterfly” this past Friday… I hanged out with 5 different groups of friends in one night.
D: “Oh wow!! How did you manage that?”

It's a word/title that is usually used to describe someone that is popular. Often times those people are friendly or pretty, but it is not always the case. It is not always used to describe popularity alone, it could also be describing someone who is friendly to strangers. Typically a word used to describe females.

someone who flirts alot and is somewhat easy, could also be known as a slut, normally used by elders that want to be nice in the way they talk about that girl that you brought home last night, or the one that there glad your just friends with

wow i'm so glad you turned her down man, my dad said shes quite a social butterfly.. haha.. you know what that means